In Shakespeare's play "Hamlet," the lead character’s lover, Ophelia, becomes unhinged.

When she makes her final appearance of the play, she hands her brother Laertes sprigs of fresh rosemary, saying: "There's rosemary, that's for remembrance. Pray, love, remember."

Rosemary has long been thought to have memory-boosting properties, and now modern science is backing up this theory.

In a study presented to the British Psychological Society, researchers found that children in a room scented with rosemary did significantly better on memory tasks than those who didn't get a whiff of the herb.

These findings line up with an earlier study the team did that found that when adults were exposed to higher concentrations of rosemary aroma, they performed better on cognitive tests.

Scientists think a compound in rosemary called 1,8-cineole might help boost an important neurotransmitter in the brain.

To enjoy rosemary's benefits, you can make rosemary oil by adding a sprig of rosemary to a bottle of olive oil. Use on salads and chicken.

Or grow a houseplant or outdoor bush and enjoy the fragrance.

Considering aromatherapy? Use only pure essential oil (no phthalates, please) in a diffuser — and use it carefully. If applying topically, first dilute in a carrier oil to avoid skin irritation.

Pregnant and breastfeeding? No essential rosemary oil for you, in any form.

And no one should ever ingest it. The Cleveland Clinic says: "Although its common use as an herb suggests low toxicity ... it can be toxic [if taken internally] even at low doses ..."